Boring tool



NOV.Y7, l939. BARNES 2,179.029

BORING TOOL I Filed Nov. 2, 1938 27 Inventor Ena? Earner memes Nov. 7, 1939' I 2,1 79,029'

- UNITED STATES, PATENT OFFICE some room Ernest Barnes, Gilroy, Calif. p

' Application November 2, 1938, Serial No. 238,484

2 Claims. (01. ii-69) This invention relates to new and useful imextending slots 28, extending upwardly from the provements in tools and more particularly to a. lower edge thereof as from the cutting tip 29 of boring tool adapted to bore openings in metal the depending cutting formation 30 which are work in a quick and accurate manner. further defined by short'inwardly extending and Another important object of the inventionis spirally directed slots 3|. 5 to provide a boring implement which includes a While the foregoing specification sets forth bit and cutting element, the bit being employed the invention in specific terms, it is to be underfor first forming a centering opening for the stood that numerous changes in the shape, size final opening to be cut. and materials may be resorted to without de- These and other objects and advantages of the parting from the spirit and scope of the inven- 10 invention will become apparentto the reader of tion as claimed hereinafter.

the following specification. Having described the invention, what is claimed In the drawing: as new is Figure 1 is a side elevational view of a modified 1. A boring tool comprising a body, said body 'form, such as will be especially adapted for use. being internally threaded, a cutting cylinder ex- 15 on drill presses. 4 tending therefrom one end of the cylinder being Figure 2 is an end elevational view showing externally threaded for disposition in the interthe cutting sldrt'oi' the form of the invention nallythreaded headand having its opposite end shown in Figure 1. formed to provide cutting teeth, said teeth hav- Figure 3 is a fragmentary detailed sectional ing cutting edges, said cylinder being formed view taken substantially on a line 3-8 of 313- with inwardly and spirally directed slots extendure 2. ing from the cutting points ofthe teeth.

Referring to the drawing wherein like nu- Y 2. A boring tool comprising a body. said bodv merals designate like parts, it can be seen that being internally threaded. a cutting cylinder exthe tool is generally referred to by numeral ll tending therefrom, one end of the cylinder being and consists of the head l9 from which extends threaded for disposition in the inter-. the shank 20 having the enlarged portion 2| nally threaded head'and having its opposite end provided with the keyway 22 therein. The shank formed to provide cutting teeth, 5 d teeth hav-.

20 and enlargement 2| are hollow to receive the ing cutting edges, said cylinder being formed 7 3 shank portion of the centering bit 23. The upper with inwardly and spirally directed'slots extend portion of the shank 20 is tapered as at 24 for ing from the cutting points-of the teeth, said w insertion into the chuck of the drilling'machine. body having an opening therein, and a bit ex- The head portion. i9 is provided. with a detending from the body andbeingheld in" the pending internally threaded skirt 2! forreceivopening, said bit extending centrally through the 3 ing the upper enlarged and externally threaded said iii-M1 8 ylinder.

portion 26 of the drilling-cylinder 21. This cyl- -inderisprovidedwithspirallydirectedupwardly 

